Learning and memory

Question 1

what is an engram

Answer 1

a hypothetical permanent biochemical or physical change in the brain caused by a memory

Question 2

how did Lashley’s experiments provide evidence for the theory of engrams

Answer 2

puts rats in mazes

showed that large areas of cerebral cortex had to be destroyed in order to prevent learning of complex tasks and this had little effect on simple tasks

Question 3

where do we currently think engrams are located

Answer 3

places related to processing the memory

Question 4

what is associative learning

Answer 4

As cells fire simultaneously they increase the synaptic associations. This
results in networks of cells which are synaptically linked

Question 5

what is habituation

Answer 5

– decrease in response (& NT release ) with repeated stimulus

Question 6

what is sensitisation

Answer 6

increase in response with repeated stimulation - mediated by an interneurone

Question 7

what is long term potentiation

Answer 7

a long term increase in synaptic strength following high frequency stimulation of a chemical synapse

aka a strengthening of synpapses between cells

Question 8

what is long term depression

Answer 8

a reduction in the eficacy of synapses following a long patterned stimulus

Question 9

what is short term memory

Answer 9

a very brief memory, either from an external stimulus or retrieval of a long term memory

can be displaced by another stimulus

can be extended into working memory by repition in a phonic loop, or chunking which links familiar chunks together

Question 10

what is working memory

Answer 10

the maintenence and integration of information in an active state to a breif time in order to acheive a short term task

may be the repeated reactivation of short term memory or recalled long term memory

after may be encoded into long term memory or elapse

Question 11

what can long term memory be subdivided into

Answer 11

declarative (Conscious) and non declarative (unconscious)

Question 12

what part of the brain is involved in declarative memory

Answer 12

medial temporal lobe

Question 13

what part of the brain is involved in non declarative memory

Answer 13

lower areas of the brain- hypothalamus, amygdala, basal ganglia and cerebellum

Question 14

what are some of the components of non declarative memory

Answer 14

procedural- habits and skills

habituation, sensitisation, conditioning, emotianal responses

Question 15

what are the 4 parts of memory

Answer 15

encoding, storage, retrieval, consolidation

Question 16

describe the process of memory formation

Answer 16

events are encoded in the hippocampus, and a reference is made to their memory location- hippocampal index

If this information is recalled prior to consolidation, the hippocampus performs the
retrieval from its index of the events

After consolidation of the memory retrieval can be initiated directly from the sensory
cortices

Question 17

how can PTSD be treated

Answer 17

plasticity in the long term memory- pts are asked to relive events leading to the PTSD and then given a beta blocker which blocks re consolidation

Question 18

what is consolidation a result of

Answer 18

physical/ morphological changes at the synapse

LTM is predominantly in the cortex

Question 19

what structures are involved in consolidating non declarative memory involving movement and procedural memory

Answer 19

corpus striatum (caudate nucleus and putamen

Question 20

what type of memory is the cerebelum involved in

Answer 20

fine motor learning including speech movements

Question 21

describe patient HM

Answer 21

operation to remove part of the medial temporal lobes bilaterally to treat epilepsy

Question 22

describe the effects on HM

Answer 22

profound retrograde and anterograde amnesia
inability to remember people he had just met, his age, the death of his mother

inability to consolidate declarative long term memories

no effect on perception, intelligence or personality

was able to learn non declarative memories

Question 23

what is dissociated amnesia

Answer 23

amnesia occuring without any other deficits

Question 24

what structures can cause anterograde amnesia

Answer 24

anterior or dorsomedial nuclei of the thalamus, Mammillary

bodies, temporal lobes

Question 25

what is the role of the dorsomedial nucleus of the thalamus

Answer 25

receives input from temporal lobe structures like the amygdala which is then relayed to the frontal cortex- executive function

Question 26

what is the role of the diencephalon in amnesia

Answer 26

there is a functional link between between the dorsomedial thalamus and the medial temporal lobe in memory consolidation

Question 27

what lesion can cause a loss of non declarative memory

Answer 27

striatum of the basal nuclei

involved in huntingtons disease